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      <title>SpringBoot+UniApp实现WebSocket通讯 - 交互式测验</title>
      <style>
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          border: 1px solid #dee2e6;
          border-radius: 8px;
          padding: 15px;
          margin-bottom: 12px;
          cursor: pointer;
          transition: background-color 0.2s ease, border-color 0.2s ease;
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        .option-item:hover {
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        .option-item.selected {
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            border-color: #4a90e2;
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        .quiz-footer {
          padding: 20px 30px;
          display: flex;
          justify-content: space-between; /* 将按钮分布在两侧 */
          align-items: center;
          min-height: 65px; /* Reserve space */
        }

        .nav-btn {
          background-color: #4a90e2;
          color: white;
          border: none;
          border-radius: 8px;
          padding: 10px 20px;
          font-size: 16px;
          font-weight: 500;
          cursor: pointer;
          transition: background-color 0.2s ease, transform 0.2s ease;
          box-shadow: 0 4px 12px rgba(0,0,0,0.15);
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        #next-btn {
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        .nav-btn:hover {
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        .nav-btn:disabled {
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        .result-box {
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        .result-box.correct {
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        .source-text {
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            margin-top: 15px;
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            font-size: 15px;
            line-height: 1.6;
            display: none; /* 默认隐藏 */
        }
      </style>
    </head>
    <body>
      <div class="main-wrapper">
          <div class="quiz-container">
            <div class="quiz-header">
              <h1>SpringBoot+UniApp实现WebSocket通讯 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
            <div id="quiz-content">
                <div class="quiz-body">
                    <div class="progress-bar">
                        <div id="progress-indicator"></div>
                    </div>
                    <div id="question-container">
                      <p id="question-text"></p>
                      <ul class="options-list" id="options-list"></ul>
                    </div>
                    <div id="result-container"></div>
                    <div id="hint-container" class="hint-container"></div>
                </div>
                <div class="quiz-footer" id="quiz-footer">
                  <button id="prev-btn" class="nav-btn">上一题</button>
                  <button id="hint-btn" class="nav-btn" style="background-color: #ffc107; color: #333; box-shadow: 0 4px 12px rgba(255,193,7,0.3);">提示</button>
                  <button id="next-btn" class="nav-btn">下一题</button>
                </div>
            </div>
          </div>
      </div>

      <script>
        const quizData = [
  {
    "question": "根据文档，与传统的HTTP轮询（Polling）相比，WebSocket协议最核心的优势是什么？",
    "options": [
      "WebSocket协议完全取代了HTTP，可以用于所有Web请求。",
      "WebSocket基于UDP协议，因此网络延迟更低。",
      "WebSocket建立持久性连接并支持全双工通讯，允许服务器主动推送数据，从而节省了服务器资源和带宽。",
      "WebSocket协议天生比HTTPS更安全，因为它有自己独立的加密层。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "文档的核心论点是HTTP的单向性和轮询的资源浪费问题。WebSocket通过建立一次握手后的持久性TCP连接，实现了全双工通信，允许服务端在有数据更新时主动推送给客户端，避免了客户端不断发起无效请求，从而极大地节省了服务器资源和网络带宽。",
    "source": "文档中「引言」和「WebSocket简介」部分",
    "hint": "思考一下，文档开头描述的HTTP轮询机制存在什么“缺陷”？WebSocket是如何解决这个缺陷的？"
  },
  {
    "question": "在文档提供的基于`netty-websocket-spring-boot-starter`的实现中，哪个注解是用来声明一个Java类为WebSocket服务器端点的？",
    "options": [
      "@OnOpen",
      "@RestController",
      "@ServerEndpoint",
      "@WebSocketController"
    ],
    "correctAnswerIndex": 2,
    "explanation": "文档中明确指出，`@ServerEndpoint`注解用于将一个类注册为一个WebSocket端点。该注解的属性（如path, port, host）定义了客户端如何连接到这个端点。而其他选项如`@OnOpen`是生命周期回调注解，`@RestController`用于HTTP API，`@WebSocketController`则不是该框架使用的标准注解。",
    "source": "文档中「WebSocket注解说明」部分",
    "hint": "哪个注解包含了所有端点的配置项，例如访问路径（path）和端口（port）？"
  },
  {
    "question": "当一个WebSocket连接成功建立后，服务端哪个注解所标记的方法会被立即回调执行？",
    "options": [
      "@OnMessage",
      "@BeforeHandshake",
      "@OnOpen",
      "@OnClose"
    ],
    "correctAnswerIndex": 2,
    "explanation": "`@OnOpen`注解用于标记一个方法，该方法会在WebSocket连接成功建立并准备好进行通信时被调用。`@BeforeHandshake`发生在连接建立之前，用于握手阶段的验证。`@OnMessage`在接收到消息时触发，`@OnClose`在连接关闭时触发。",
    "source": "文档中「WebSocket注解说明」部分",
    "hint": "“Open”这个词通常意味着什么？在连接的生命周期中，它处于哪个阶段？"
  },
  {
    "question": "文档中实现的聊天功能里，`SessionManager`这个组件的核心职责是什么？",
    "options": [
      "负责对客户端发送的聊天内容进行安全过滤和审查。",
      "集中管理所有在线客户端的Session对象，以便于查找特定用户并向其转发消息。",
      "将用户的聊天记录持久化到数据库中。",
      "为每个客户端连接创建一个独立的线程来处理消息。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "根据文档中`SessionManager`的实现代码，它内部使用了一个`ConcurrentHashMap`来存储每个客户端的唯一标识（token）和对应的`Session`对象。这使得在`@OnMessage`方法中，服务器可以根据消息中的接收人标识，从`SessionManager`中获取到目标客户端的`Session`，从而实现点对点消息发送。",
    "source": "文档中「实现聊天功能」-「1、创建session管理器」部分",
    "hint": "查看`SessionManager`类中的`add`, `get`, `remove`方法，它们操作的主要对象是什么？"
  },
  {
    "question": "文档中提到，`@ServerEndpoint`注解的类实例是如何被管理的？这对于状态管理有何重要意义？",
    "options": [
      "该类的实例是单例的，所有客户端共享同一个实例，状态通过Session ID区分。",
      "每次收到客户端消息时，都会创建一个新的临时实例来处理该消息。",
      "每个客户端连接成功时，都会创建一个新的该类的实例，因此实例变量（非静态）是线程安全的，专属于单个连接。",
      "实例由Spring容器默认管理为单例，需要开发者手动配置为原型（Prototype）作用域。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "文档中特别强调：“@ServerEndpoint 每个客户端连接，都会生成一个实例，所以需要在单独有一个bean来管理session。” 这意味着该类的实例与每个WebSocket连接一一对应，其生命周期也与连接绑定。因此，在该实例中定义的成员变量（非静态）对于每个客户端连接是独立的，不会发生多线程共享问题，但如果要在不同客户端实例间共享数据，就需要借助像`SessionManager`这样的单例Bean。",
    "source": "文档中「搭建WebSocket服务器」-「3、WebSocket配置类」部分",
    "hint": "文档中有一句加粗的“注意”提醒，它描述了`@ServerEndpoint`注解的类与客户端连接之间的关系。"
  },
  {
    "question": "根据文档，当需要通过WebSocket传输图片这类二进制数据时，推荐采用哪种处理方式？",
    "options": [
      "将二进制数据直接封装在JSON对象中传输。",
      "先将二进制数据进行Base64编码转换成字符串，然后再进行传输。",
      "通过HTTP协议的POST请求上传文件，WebSocket仅用于传输通知。",
      "将原始的byte数组直接发送，因为WebSocket原生支持二进制。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "文档在「WebSocket传递二进制数据」一节中明确描述了实现流程：“先把二进制数组转成byteArray，然后把byteArray用Base64编码得到一个字符串，然后进行传递。” 这种方式可以将二进制数据安全地嵌入到基于文本的协议（如JSON）中，简化了跨平台和跨语言的数据处理。",
    "source": "文档中「WebSocket传递二进制数据」部分",
    "hint": "文档提供了一个名为`Base64Utils`的工具类，它的核心功能是什么？"
  },
  {
    "question": "在Spring Cloud Gateway中路由WebSocket请求时，配置文件的`uri`字段应该使用什么协议头？",
    "options": [
      "http://",
      "ws://",
      "tcp://",
      "rpc://"
    ],
    "correctAnswerIndex": 1,
    "explanation": "文档中的「gateway 路由WebSocket请求」部分给出了一个清晰的YAML配置示例。为了让Gateway能正确地代理WebSocket流量，`uri`必须使用`ws://`（非加密）或`wss://`（加密）协议方案，而不是常规的`http://`。",
    "source": "文档中「gateway 路由WebSocket请求」部分",
    "hint": "客户端连接WebSocket服务器时使用的URL协议是什么？网关的配置需要与之对应。"
  }
];
        console.log("Quiz Data:", JSON.parse(JSON.stringify(quizData))); // 添加这行用于调试，以可展开的JSON格式输出
        
        let currentQuestionIndex = 0;
        let score = 0;
        // 存储每个问题的回答状态
        const userAnswers = new Array(quizData.length).fill(null); 

        const questionTextEl = document.getElementById('question-text');
        const optionsListEl = document.getElementById('options-list');
        const resultContainerEl = document.getElementById('result-container');
        const quizContentEl = document.getElementById('quiz-content');
        const progressIndicatorEl = document.getElementById('progress-indicator');
        const prevBtn = document.getElementById('prev-btn');
        const nextBtn = document.getElementById('next-btn');
        const hintBtn = document.getElementById('hint-btn');
        const hintContainerEl = document.getElementById('hint-container');

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          resultContainerEl.innerHTML = '';
          optionsListEl.innerHTML = '';
          hintContainerEl.style.display = 'none'; // 隐藏提示
          
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            showFinalScore();
            return;
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            li.textContent = optionText;
            li.dataset.index = index; // Store index in a data attribute
            // 如果这道题已经回答过，恢复状态
            if (userAnswers[currentQuestionIndex] !== null) {
                if (index === userAnswers[currentQuestionIndex]) {
                    li.classList.add('selected');
                }
            }
            optionsListEl.appendChild(li);
          });

          // 如果已经回答过，直接显示结果
          if (userAnswers[currentQuestionIndex] !== null) {
              const isCorrect = userAnswers[currentQuestionIndex] === currentQuestion.correctAnswerIndex;
              showResult(isCorrect, currentQuestion);
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          updateNavigationButtons();
          updateProgress();
        }

        function selectOption(optionIndex) {
            userAnswers[currentQuestionIndex] = optionIndex;
            const currentQuestion = quizData[currentQuestionIndex];
            const isCorrect = optionIndex === currentQuestion.correctAnswerIndex;

            // 重新计算分数
            score = userAnswers.reduce((acc, answer, index) => {
                return answer === quizData[index].correctAnswerIndex ? acc + 1 : acc;
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            showResult(isCorrect, currentQuestion);
            updateNavigationButtons();
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            nextBtn.style.display = 'block';
            hintBtn.style.display = 'block'; // 显示提示按钮

            prevBtn.disabled = currentQuestionIndex === 0;
            nextBtn.disabled = false; // 最后一题时，下一题按钮不禁用，而是用于显示报告
            nextBtn.textContent = (currentQuestionIndex === quizData.length - 1) ? '查看报告' : '下一题';
            
            // 如果当前问题没有提示，则禁用提示按钮并隐藏提示内容
            if (!quizData[currentQuestionIndex].hint) {
                hintBtn.disabled = true;
                hintContainerEl.style.display = 'none';
                hintContainerEl.textContent = ''; // 清除旧的提示内容
            } else {
                hintBtn.disabled = false;
            }
        }

        function showResult(isCorrect, questionData) {
            resultContainerEl.innerHTML = ''; // 清空之前的结果
            const resultBox = document.createElement('div');
            resultBox.className = `result-box ${isCorrect ? 'correct' : 'incorrect'}`;
            
            let html = `<h3>${isCorrect ? '回答正确！' : '回答错误'}</h3>`;
            if (!isCorrect) {
                html += `<p><strong>正确答案是：</strong> ${questionData.options[questionData.correctAnswerIndex]}</p>`;
            }
            html += `<div class="explanation-text">${questionData.explanation}</div>`;
            html += `<div class="source-text">来源: ${questionData.source}</div>`;
            
            resultBox.innerHTML = html;
            resultContainerEl.appendChild(resultBox);

            // 禁用所有选项的点击事件，并高亮正确/错误答案
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                child.style.pointerEvents = 'none';
                // 高亮正确答案
                if (index === questionData.correctAnswerIndex) {
                    child.classList.add('correct'); // 需要添加CSS样式
                    child.style.backgroundColor = '#d4edda';
                    child.style.borderColor = '#c3e6cb';
                }
                // 如果选错了，高亮错误选项
                if (!isCorrect && index === userAnswers[currentQuestionIndex]) {
                    child.classList.add('incorrect'); // 需要添加CSS样式
                    child.style.backgroundColor = '#f8d7da';
                    child.style.borderColor = '#f5c6cb';
                }
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        }

        function goToNextQuestion() {
            if (currentQuestionIndex < quizData.length - 1) {
                currentQuestionIndex++;
                loadQuestion();
            } else {
                showFinalScore();
            }
        }

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            if (currentQuestionIndex > 0) {
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                loadQuestion();
            }
        }
        
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                hintContainerEl.textContent = currentQuestion.hint;
                hintContainerEl.style.display = 'block';
            } else {
                hintContainerEl.style.display = 'none';
            }
        }

        function showFinalScore() {
            document.querySelector('.quiz-body').style.display = 'none';
            document.getElementById('quiz-footer').style.display = 'none';

            const correctCount = score;
            const totalQuestions = quizData.length;
            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

            const finalScoreHtml =
                '<div class="final-score-container">' +
                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

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                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  